1. Field of the Invention
The present invention relates to a camera system comprising a camera head having an image taking optical system and an image sensor, and a camera main frame for receiving an image signal from the camera head that is mounted on an exchangeable basis to perform an image processing, and a main frame adapter, and a head adapter.
2. Description of the Related Art
There is proposed a camera system wherein when a camera head, which has an image taking optical system and an image sensor, is detachably mounted on a camera main frame for performing a signal processing, it is possible to performs photography making the best use of photographic functions of the camera head. According to such a camera system, it is considered that the selection of the camera head makes it possible to freely performs photography changing focal length and focal range in a similar fashion to that of the conventional interchangeable lens, and further it is considered that color photography can be freely performed with color shades of an image sensor having various color filters.
In the camera system as mentioned above, it is convenient not only that photography can be performed when the camera head is in a state that it is mounted on the camera main frame, but also that photography can be performed through a remote control even when the camera head is in a state that the camera head is separated from the camera main frame.
Hence, there are proposed schemes in which the camera head and the camera main frame are each provided with a radio communication apparatus, so that communications of image signals and control signals can be performed on a wireless basis (cf. for example, Japanese Patent Application Laid Open Gazettes TokuKai 2004-201073, TokuKai 2004-173036, TokuKai 2004-187127, and TokuKai 2004-88396).
According to Japanese Patent Application Laid Open Gazettes TokuKai 2004-201073, in view of operability at the user side, when the camera head is mounted on the camera main frame, photography can be performed, and when the camera head is in a state that the camera head is separated from the camera main frame, photography according to a remote control can be performed in such a manner that a sensor and the like detect the state of the separation and automatically turn on a radio communication apparatus.
In the event that photography is performed in accordance with such a remote control, there is a possibility that it happens that the camera main frame cannot perform signal processing unless a frame rate is down in accordance with a transmission capacity of the radio communication apparatuses of both the camera head and the camera main frame. Thus, there is proposed a scheme that image signals are surely transmitted from the camera head to the camera main frame in such a manner that processing time for a frame of image signal is expanded, and/or the number of pixel numbers is reduced so that a frame rate is down (cf. for example, Japanese Patent Application Laid Open Gazettes TokuKai 2004-173036, and TokuKai 2004-187127).
However, the radio communication apparatuses, which are needed when the camera head and the camera main frame are separated from one another, are not needed when the camera head is mounted on the camera main frame. The radio communication apparatuses are not completely needed for a person who does not intend to perform photography in the state of the separation of the camera head and the camera main frame. Intention to provide the radio communication apparatuses inside the camera head and the camera main frame would bring about an enlargement of the camera head and the camera main frame.
In order to avoid the problems as mentioned above, according to Japanese Patent Application Laid Open Gazette TokuKai 2004-88396, there is proposed a system that a camera head and a camera main frame, which are each provided with a radio communication apparatus, are prepared as dedicated devices, and a person, who wishes to perform photography according to a remote control, buys such dedicated devices.
However, the above-mentioned system involves such a problem that a person, who wishes to perform photography through attachment of a camera head to a camera main frame, and also wishes to perform photography through separation of the camera head to the camera main frame, is obliged to buy the dedicated devices in addition to the original camera system.